# 🚗 Smart Parking Finder - Technical Specification

## 📋 Project Overview

A responsive web application that helps users find and navigate to the nearest available parking lots using OpenStreetMap and Valhalla Routing Engine with real-time availability and turn-by-turn navigation.

## 🎯 Core Features

### 🔍 Location & Discovery
- GPS-based user location detection
- Interactive map with nearby parking lots
- Real-time availability display
- Distance and direction calculation
- Smart parking suggestions

### 🗺️ Navigation & Routing
- Valhalla-powered route generation
- Turn-by-turn directions
- Visual route display on map
- Estimated arrival time
- Alternative route options

### 📊 Parking Information
- Name, address, and contact details
- Real-time available slots
- Pricing per hour
- Operating hours
- Amenities and features

## 🏗️ System Architecture

```
┌─────────────────┐    ┌─────────────────┐    ┌─────────────────┐
│   Frontend      │    │   Backend API   │    │   Database      │
│   (Next.js)     │◄──►│   (NestJS)      │◄──►│ PostgreSQL +    │
│                 │    │                 │    │ PostGIS         │
└─────────────────┘    └─────────────────┘    └─────────────────┘
                                │
                                ▼
                       ┌─────────────────┐
                       │ Valhalla Engine │
                       │   (Docker)      │
                       └─────────────────┘
```

## 🔧 Technology Stack

### Frontend
- **Framework**: Next.js 14 with TypeScript
- **Map Library**: React Leaflet + OpenStreetMap
- **UI Framework**: Tailwind CSS with custom branding
- **State Management**: React Query + Zustand
- **HTTP Client**: Axios with interceptors
- **PWA Support**: Next.js PWA plugin

### Backend
- **Framework**: NestJS with TypeScript
- **Database ORM**: TypeORM with PostGIS
- **Caching**: Redis for route caching
- **API Documentation**: Swagger/OpenAPI
- **Authentication**: JWT + Passport.js
- **Rate Limiting**: Express rate limiter

### Infrastructure
- **Routing Engine**: Valhalla (Docker)
- **Database**: PostgreSQL 15 + PostGIS 3.3
- **Deployment**: Docker Compose
- **Monitoring**: Prometheus + Grafana
- **CDN**: CloudFlare for static assets

## 📊 Database Schema

```sql
-- Parking lots table
CREATE TABLE parking_lots (
    id SERIAL PRIMARY KEY,
    name VARCHAR(255) NOT NULL,
    address TEXT NOT NULL,
    location GEOGRAPHY(POINT, 4326) NOT NULL,
    lat DOUBLE PRECISION NOT NULL,
    lng DOUBLE PRECISION NOT NULL,
    hourly_rate DECIMAL(10,2),
    open_time TIME,
    close_time TIME,
    available_slots INTEGER DEFAULT 0,
    total_slots INTEGER NOT NULL,
    amenities JSONB DEFAULT '{}',
    contact_info JSONB DEFAULT '{}',
    created_at TIMESTAMP DEFAULT NOW(),
    updated_at TIMESTAMP DEFAULT NOW()
);

-- Spatial index for location queries
CREATE INDEX idx_parking_lots_location ON parking_lots USING GIST (location);

-- Users table (for favorites, history)
CREATE TABLE users (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    email VARCHAR(255) UNIQUE,
    name VARCHAR(255),
    preferences JSONB DEFAULT '{}',
    created_at TIMESTAMP DEFAULT NOW()
);

-- Parking history
CREATE TABLE parking_history (
    id SERIAL PRIMARY KEY,
    user_id UUID REFERENCES users(id),
    parking_lot_id INTEGER REFERENCES parking_lots(id),
    visit_date TIMESTAMP DEFAULT NOW(),
    duration_minutes INTEGER,
    rating INTEGER CHECK (rating >= 1 AND rating <= 5)
);

-- Real-time parking updates
CREATE TABLE parking_updates (
    id SERIAL PRIMARY KEY,
    parking_lot_id INTEGER REFERENCES parking_lots(id),
    available_slots INTEGER NOT NULL,
    timestamp TIMESTAMP DEFAULT NOW(),
    source VARCHAR(50) DEFAULT 'sensor'
);
```

## 🚀 API Endpoints

### Parking Discovery
```typescript
// GET /api/parking/nearby
interface NearbyParkingRequest {
  lat: number;
  lng: number;
  radius?: number; // meters, default 4000
  maxResults?: number; // default 20
  priceRange?: [number, number];
  amenities?: string[];
}

interface NearbyParkingResponse {
  parkingLots: ParkingLot[];
  userLocation: { lat: number; lng: number };
  searchRadius: number;
}
```

### Route Planning
```typescript
// POST /api/routing/calculate
interface RouteRequest {
  origin: { lat: number; lng: number };
  destination: { lat: number; lng: number };
  costing: 'auto' | 'bicycle' | 'pedestrian';
  alternatives?: number;
}

interface RouteResponse {
  routes: Route[];
  summary: {
    distance: number; // km
    time: number; // minutes
    cost: number; // estimated fuel cost
  };
}
```

### Real-time Updates
```typescript
// WebSocket: /ws/parking-updates
interface ParkingUpdate {
  parkingLotId: number;
  availableSlots: number;
  timestamp: string;
  confidence: number; // 0-1
}
```

## 🎨 Brand Integration

Based on the existing assets in `/assets/`:
- **Logo**: Use Logo.png for header branding
- **Logo with Slogan**: Use Logo_and_sologan.png for splash screen
- **Location Icons**: Integrate Location.png and mini_location.png for map markers

### Color Palette
```css
:root {
  --primary: #E85A4F;      /* LACA Red */
  --secondary: #D73502;    /* Darker Red */
  --accent: #8B2635;       /* Deep Red */
  --success: #22C55E;      /* Green for available */
  --warning: #F59E0B;      /* Amber for limited */
  --danger: #EF4444;       /* Red for unavailable */
  --neutral: #6B7280;      /* Gray */
}
```

## 📱 UI/UX Design

### Layout Structure
```
┌─────────────────────────────────────────┐
│ Header [Logo] [Search] [Profile]        │
├─────────────────┬───────────────────────┤
│ Sidebar         │ Map View              │
│ - Filters       │ - User location       │
│ - Parking List  │ - Parking markers     │
│ - Selected Info │ - Route overlay       │
│ - Directions    │ - Controls            │
└─────────────────┴───────────────────────┘
```

### Responsive Breakpoints
- **Mobile**: < 768px (full-screen map with drawer)
- **Tablet**: 768px - 1024px (split view)
- **Desktop**: > 1024px (sidebar + map)

## 🐳 Docker Configuration

### Valhalla Setup
```dockerfile
# Dockerfile.valhalla
FROM ghcr.io/gis-ops/docker-valhalla/valhalla:latest

# Copy OSM data
COPY ./osm-data/*.pbf /custom_files/

# Configuration
COPY valhalla.json /valhalla.json

EXPOSE 8002

CMD ["valhalla_service", "/valhalla.json"]
```

### Docker Compose
```yaml
version: '3.8'

services:
  frontend:
    build: ./frontend
    ports:
      - "3000:3000"
    environment:
      - NEXT_PUBLIC_API_URL=http://backend:3001
    depends_on:
      - backend

  backend:
    build: ./backend
    ports:
      - "3001:3001"
    environment:
      - DATABASE_URL=postgresql://user:pass@postgres:5432/parking_db
      - REDIS_URL=redis://redis:6379
      - VALHALLA_URL=http://valhalla:8002
    depends_on:
      - postgres
      - redis
      - valhalla

  postgres:
    image: postgis/postgis:15-3.3
    environment:
      - POSTGRES_DB=parking_db
      - POSTGRES_USER=user
      - POSTGRES_PASSWORD=pass
    volumes:
      - postgres_data:/var/lib/postgresql/data

  redis:
    image: redis:7-alpine
    ports:
      - "6379:6379"

  valhalla:
    build:
      context: .
      dockerfile: Dockerfile.valhalla
    ports:
      - "8002:8002"
    volumes:
      - ./valhalla-data:/valhalla-data

volumes:
  postgres_data:
```

## 🔐 Security Considerations

### Frontend Security
- Content Security Policy (CSP)
- HTTPS enforcement
- API key protection
- Input sanitization

### Backend Security
- Rate limiting per IP
- JWT token validation
- SQL injection prevention
- CORS configuration

### Infrastructure Security
- Database encryption at rest
- SSL/TLS certificates
- Network segmentation
- Regular security updates

## 📈 Performance Optimization

### Frontend Optimization
- Code splitting by routes
- Image optimization with Next.js
- Service worker for caching
- Lazy loading for map components

### Backend Optimization
- Database query optimization
- Redis caching for frequent requests
- Connection pooling
- Response compression

### Database Optimization
- Spatial indexes for geo queries
- Query result caching
- Read replicas for scaling
- Partitioning for large datasets

## 🚀 Deployment Strategy

### Development
```bash
# Local development setup
docker-compose -f docker-compose.dev.yml up -d
npm run dev:frontend
npm run dev:backend
```

### Production
```bash
# Production deployment
docker-compose -f docker-compose.prod.yml up -d
```

### CI/CD Pipeline
1. **Build**: Docker images for each service
2. **Test**: Unit tests, integration tests, E2E tests
3. **Deploy**: Blue-green deployment strategy
4. **Monitor**: Health checks and performance metrics

## 📊 Monitoring & Analytics

### Application Metrics
- Response times
- Error rates
- User engagement
- Route calculation performance

### Business Metrics
- Popular parking locations
- Peak usage times
- User retention
- Revenue per parking lot

## 🔄 Future Enhancements

### Phase 2 Features
- Parking reservations
- Payment integration
- User reviews and ratings
- Push notifications for parking alerts

### Phase 3 Features
- AI-powered parking predictions
- Electric vehicle charging stations
- Multi-language support
- Offline mode with cached data

## 📋 Implementation Timeline

### Week 1-2: Foundation
- Project setup and infrastructure
- Database schema and migrations
- Basic API endpoints

### Week 3-4: Core Features
- Map integration with Leaflet
- Parking lot display and search
- User location detection

### Week 5-6: Navigation
- Valhalla integration
- Route calculation and display
- Turn-by-turn directions

### Week 7-8: Polish
- UI/UX improvements
- Performance optimization
- Testing and bug fixes

### Week 9-10: Deployment
- Production setup
- CI/CD pipeline
- Monitoring and analytics

## 🏁 Success Metrics

### Technical KPIs
- Page load time < 2 seconds
- Route calculation < 3 seconds
- 99.9% uptime
- Zero security vulnerabilities

### User Experience KPIs
- User retention > 60%
- Average session time > 5 minutes
- Route accuracy > 95%
- User satisfaction score > 4.5/5

This comprehensive specification provides a solid foundation for building a world-class parking finder application with modern web technologies and best practices.